If you hit a weakspot and quickly follow it up with a bodyshot, no hitmarker will show for the bodyshot. Here is a video demonstrating this (I can’t upload to this forum directly for some reason).
Similarly, if you get a kill then quickly follow it up with a weakspot or bodyshot, then no hitmarker will show for either the weakspot or bodyshot.
And if you hit a bodyshot and quickly follow it up with a no-damage hit (such as to a Bulwark shield), then the hitmarker for the no-damage hit will not show.
My guess is that this behavior has to do with the fading-out of the hitmarkers. Perhaps it is intentional behavior, but hitmarkers are the only reliable way to tell if I’ve hit something in a multiplayer game. I’d rather have immediate feedback on whether I’ve hit something than for my kill/weakspot hitmarkers to linger.